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Full text of "AWPA P5: Standard for Waterborne Preservative"

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By Authority Of 

THE UNITED STATES OF AMERICA 

Legally Binding Document 



By the Authority Vested By Part 5 of the United States Code § 552(a) and 
Part 1 of the Code of Regulations § 51 the attached document has been duly 
INCORPORATED BY REFERENCE and shall be considered legally 
binding upon all citizens and residents of the United States of America. 
HEED THIS NOTICE : Criminal penalties may apply for noncompliance. 




Document Name: AWPA P5 : Standard for Waterborne Preservative 



CFR Section(s): 7 CFR 1 728 .20 1 (i)( 1 )(iii)(A) 



Standards Body: American Wood Preservers Association 



AMiftlCAM WOOD-PRESERVERS' ASSOCIATION 
STANDARD 

(This Standard is under the jurisdiction of AWPA Subcommittee P-4) 

P5-91 
STANDARDS FOR WATERBORNE PRESERVATIVES 



Note: Standard P5-90 consists of four pages dated as fol- 
lows: Pgs. 1-4, 1990 

Scope 

These standards cover waterborne preservative 
formulations expressed on the oxide basis and pre- 
scribe maximum and minimum values of acceptability 
in either solid, paste, or solution formulations for use 
in the preservative treatment of wood. 



1. ACID COPPER CHROMATE (ACC) 

1.1 Acid copper chromatc shall have the fol- 
lowing composition: 

Copper, as CuO 31.8% 

Hezavalent chromium, as CrOs 68.2% 

subject to the following tolerances: 

1.2 The analytical composition of the solid, 

paste, liquid concentrate or treating solution forms of 

the preservative may vary within the following limits : 

Min. b 
Copper, as CuO 28.0% 

Hezavalent chromium, as CrOa 63.3% 

1.3 The solid, paste, liquid concentrate or treat- 
ing solution shall be made up of water soluble 
compounds selected from the following groups each 
in excess of 95 percent purity on an anhydrous basis: 
Bivalent copper— e.g., copper sulfate 

Hexavalent chromium — e.g., sodium or potassium dichro- 
mate, chromium trioxide 

The commercial preservative shall be labeled as 
to its total content of active ingredients listed in the 
first paragraph. 

1.4 Tests to establish conformity with the fore- 
going requirements shall be made in accordance with 
the standard methods of the American Wood-Pre- 
servers' Association.* (See Standard A2.) 



6 The composition of treating solutions in use may devi- 
ate outside the limits specified in paragraphs 1.2, 2.2, 3.2, 
4.2, 3.2, 6.2 and 7.2 provided: a. The preservative reten- 
tion in treated material is determined by assay and the 
retention so determined conforms to the requirements speci- 
fied in the Table of para. 3.1 in Standard Cl. b. Immediate 
action is taken to adjust the composition of the treating 
solution. 

* Acetic acid may be used if desired to adjust pH of treat- 
ing solution to conform to paragraph 1.4. 



2. AMMONIACAL COPPER ARSENATE 

(ACA) 

2.1 Ammoniacal copper arsenate shall have the 
following composition: 

Copper, as CuO 49.8% 

Arsenic, as A&Cfe 50.2% 

subject to the tolerances listed in paragraph 2.2. 

The above shall be dissolved in a solution of 

ammonia (NH S ) in water. The weight of ammonia 

contained in a treating solution shall be a minimum 

of 1.5 times the weight of copper expressed on the 

oxide basis. To aid in solution, not over 1.7 percent 

of glacial acetic acid may be added. 

2.2 The analytical composition of the solid, 

paste, liquid concentrate or treating solution forms of 

the preservative may vary within the following limits : 

Min.' 

Copper, as CuO 47.7% 

Arsenic, as AscOb 47.6% 

2.3 The treating solution shall contain bivalent 
copper and pentavalent arsenic derived from com- 
pounds in excess of 95 percent purity on an anhy- 
drous basis. 

The commercial preservative shall be labeled as 
to its total content of active ingredients listed in the 
first paragraph. 

2.4 Tests to establish conformity with the fore- 
going requirements shall be made in accordance with 
the standard methods of the American Wood -Pre- 
servers* Association, (See Standard A2.) 

2.5 The valency state of the arsenic component 
of ACA treating solutions shall be determined in 
accordance with Section 13 of AWPA Standard A2, 
to ensure that the arsenic is in the pentavalent form. 

3. AMMONIACAL COPPER ZINC ARSE- 
NATE (ACZA) . 

3.1 Ammoniacal Copper Zinc Arsenate shall 
have the following composition : 

Copper as CuO 50.0% 

Zinc as ZnO 25.0% 

Arsenic as As 2 O s 25.0% 

Subject to the tolerances listed in Paragraph 3.2. 
The above shall be dissolved in a solution of am- 
monia (NH 3 ) in water. The weight of ammonia 



P5 — Woterbome Preservatives 



1991 



contained in a treating solution and obtained from 
ammonium hydroxide, shall be at least 1.38 times 
the weight of copper oxide. To aid in solution, it is 
also necessary that the treating solution contain am- 
monium bicarbonate (NH 4 HC0 3 ) at least equal to 
0.92 times the weight of copper oxide. 

3.2 The composition of the preservative present 
in a treating solution may vary within the following 
limits: 

Min. %" Max, %" 

Copper as CuO 45.0 55.0 

Zinc as ZnO 22.5 27.5 

Arsenic as As 2 Os 22.5 27.5 

3-3 The treating solution shall contain bivalent 
copper, bivalent zinc and pentavalent arsenic derived 
from compounds in excess of 95 percent purity on an 
anhydrous basis. 

The commercial preservative shall be labeled as 
to its total content of active ingredients listed in 
Paragraph 3.1. 

3.4 Tests to establish conformity with the fore- 
going requirements shall be made in accordance with 
the standard methods of the American Wood-Pre- 
servers' Association. 

3.5 The valency state of the arsenic component of 
ACZA treating solutions shall be determined in ac- 
cordance with Section 13 of AWPA Standard A2, to 
ensure that the arsenic is in the pentavalent form. 



CHROMATID COPPER ARSENATE 
4. TYPE A 

4.1 Chromated copper arsenate, Type A, shall 
have the following composition: 

Hexavalent chromium, as CrOa 65. 5% 

Copper, as CuO 18.1% 

Arsenic, as AssOb 164% 

subject to the following tolerances: 

4.2 The analytical composition of the solid, 

paste, liquid concentrate or treating solution forms of 

the preservative may vary within the following limits: 

Min., % Max., % b 

Hexavalent chromium, as CrOs 59.4 69.3 

Copper, as CuO 16.0 20.9 

Arsenic, as AssO, 14.7 197 



*' The composition of treating solutions in use may deviate 
outside the limits specified in paragraphs 1.2, 2.2, 3.2, 4.2, 
5.2, 6.2 and 7.2 provided: a. The preservative retention in 
treated material is determined by assay and the retention so 
determined conforms to the requirements specified in the 
Table of para. 3-1 in Standard Cl. b. Immediate action is 
taken to adjust the composition of the treating solution. 



4.3 The solid, paste, liquid concentrate or treat- 
ing solution shall be made up of water soluble 
compounds selected from the following groups each 
in excess of 95 percent purity on an anhydrous basis: 

Hexavalent chromium — e.g., potassium or sodium dichro- 

mate, chromium trioxide 
Bivalent copper — e.g., copper sulfate, basic copper carbonate, 

cupric oxide or hydroxide 
Pentavalent arsenic—eg., arsenic pentoxide, arsenic acid, so- 
dium arsenate or pyroarsenate 
Certain impurities, such as iron, lead, chloride, organic 
matter and insolubles, may result in the formation of sludge 
in CCA concentrates and /or treating solutions. Caution is 
advised in selecting raw materials and evaluating treating 
solutions. For details of these effects reference Proceedings 
AWPA 82:28. 

The commercial preservative shall be labeled as 
to its total content of active ingredients listed in the 
first paragraph. 

4.4 Tests to establish conformity with the fore- 
going requirements shall be made in accordance with 
the standard methods of the American Wood -Pre- 
servers* Association. (See Standard A2.) 

5. TYPE B 

5.1 Chromated copper arsenate, Type B, shall 
have the following composition: 

Hexavalent chromium, as CrOs 35.3% 

Copper, as CuO 19.6% 

Arsenic, as AssOs 45.1% 

subject to the following tolerances: 

5.2 The analytical composition of the solid, 

paste, liquid concentrate or treating solution forms of 

the preservative may vary within the following limits : 

Min., % Max., % b 

Hexavalent chromium, as CrO« 33.0 38.0 

Copper, as CuO 18.0 22.0 

Arsenic, as AssOa 42.0 48.0 

5.3 The solid, paste, liquid concentrate or treat- 
ing solution shall be made up of water soluble 
compounds selected from the following groups each 
in excess of 95 percent purity on an anhydrous basis : 

Hexavalent chromium — e.g., potassium or sodium dichro- 

mate, chromium trioxide 
Bivalent copper — e.g., copper sulfate, basic copper carbonate, 

cupric oxide or hydroxide 
Pentavalent arsenic — e.g., arsenic pentoxide, arsenic acid, so- 
dium arsenate or pyroarsenate 

Certain impurities, such as iron, lead, chloride, organic 
matter and insolubles, may result in the formation of sludge 
in CCA concentrates and /or treating solutions. Caution is 
advised in selecting raw materials and evaluating treating 
solutions. For details of these effects reference Proceedings 
AWPA 82:28. 

The commercial preservative shall be labeled as 

to its total content of active ingredients listed in the 

first paragraph. 

5.4 Tests to establish conformity with the fore- 
going requirements shall be made in accordance with 
the standard methods of the American Wood- Pre- 
servers' Association. (See Standard A2.) 



1991 



PS — Waferborne Preservatives 



6. TYPE C 

6.1 The active ingredients in chromated copper 
arsenate shall have the following composition: 

Hexavalent chromium, as CrOo 47-5% 

Copper, as CuO 18.5% 

Arsenic, as As*0» 34.0% 

6.2 The analytical composition of the solid, 
paste, liquid concentrate or treating solution forms of 
the preservative may vary within the following limits : 

Min., % Max., %* 

Hexavalent chromium, as CrOi __ 44.5 50.5 

Copper, as CuO 17.0 21.0 

Arsenic, as AssOb 30.0 38.0 

6.3 The solid, paste, liquid concentrate or treat- 
ing solution shall be made up of water soluble 
compounds selected from the following groups each 
in excess of 95 percent purity on an anhydrous basis: 

Hexavalent chromium — e.g., potassium or sodium dichro- 

mate, chromium (xioxide 
Bivalent copper — e.g., copper sulfate, basic copper carbonate, 

cupric oxide or hydroxide 
Pentavalent arsenic — e.g., arsenic pentoxide, arsenic acid, so- 
dium arsenate or pyroarsenate 

Certain impurities, such as iron, lead, chloride, organic 
matter and insolubles, may result in the formation of sludge 
in CCA concentrates and /or treating solutions. Caution is 
advised in selecting raw materials and evaluating treating 
solutions. For details of these effects reference Proceedings 
AWPA 82:28. 

The commercial preservative shall be labeled as 
to its total content of active ingredients listed in the 
first paragraph. 

6.4 Tests to establish conformity with the fore- 
going requirements shall be made in accordance with 
the standard methods of the American Wood-Preserv- 
ers' Association. (See Standard A2.) 

7. CHROMATED ZINC CHLORIDE 

(CZC) 

7.1 Chromated zinc chloride shall have the fol- 
lowing composition: 

Hexavalent chromium, as CrOs 20% 

Zinc, as ZnO 80% 

subject to the following tolerances: 

7.2 The analytical composition of the solid, 
paste, liquid concentrate or treating solution forms Of 
the preservative may vary within the following limits : 

Min., % b 

19 

76 



Hexavalent chromium, as CrOo 
Zinc, as ZnO 



b The composition of treating solutions in use may devi- 
ate outside the limits specified in paragraphs 1.2, 2.2, 3.2, 
4.2, 5.2, 6.2 and 7.2 provided: a. The preservative reten- 
tion in treated material is determined by assay and the 
retention so determined conforms to the requirements speci- 
fied in the Table of para. 3.1 in Standard Cl. b. Immediate 
action is taken to adjust the composition of the treating 
solution. 



7.3 Samples of chromated zinc chloride treating 
solution taken from a working tank or treating cyl- 
inder may show changes in composition as a result 
of treating operations. Such changes shall not serve 
to cause rejection of the preservative if they do not 
raise the ratio of zinc oxide to chromium trioxide to 
more than 7 to 1, and if it can be shown that the 
original fresh preservative was of the specified com- 
position. 

7.4 The solid, paste, liquid concentrate or treat- 
ing solution shall be made up of water soluble 
compounds selected from the following groups each 
in excess of 95 percent purity on an anhydrous basis: 

Hexavalent chromium— e.g., sodium dichromate, chromium 

trioxide 
Zinc — e.g., zinc chloride 

The commercial preservative shall be labeled as 
to its total content of active ingredients listed in the 
first paragraph. 

7.5 Tests to establish conformity with the fore- 
going requirements shall be made in accordance with 
the standard methods of the American Wood -Pre- 
servers' Association. (See Standard A2.) 



8. ALKYL AMMONIUM COMPOUND (AAC) 

8.1 Aklyl ammonium compound shall have the 
following composition: 

Didecylclimethylammonium chloride 

90% min. 
Dialkyldimethylammonium chlorides 
(containing C8 or C12) 10% max. 

8.2 The liquid concentrate shall be made up in 
lower ( < C4) alcohols and / or water such that the 
active ingredient is freely soluble in water. 

The commercial preservative shall be labeled as 
to its total content of active ingredients listed in the 
first paragraph. 



9. INORGANIC BORON 

9.1 Borate oxide (SBX) 

9.2 Boron as B 2 3 

9.3 The solid or treating solutions shall be made 
up of sufficient water soluble compounds, each in 
excess of 98% purity on an anhydrous basis. Accept- 
able borate salts are sodium octaborate, sodium tetra- 
borate, and sodium pentaborate. 

9.4 The commercial preservative shall be la- 
beled as to its total content of active ingredients listed 
in the second paragraph. 

Tests to establish conformity with the foregoing 
requirements shall be made in accordance with the 
standard methods of the American Wood-Preservers' 
Association. (See Standard A2.) 



P5 — Waterhome Preservatives 



1991 



10. P H OF TREATING SOLUTIONS 

10.1 The pH of waterborne preservative solu- 
tions shall be within the following limits: 

Preservative pH Limits 

ACC 3.0-7.0 

ACA Not Applicable 

ACC 2.0-3.9 

ACZA Not applicable 

CCA-Type A 1.6-2.7 

CCA-Type B 1.6-2.5 

CCA-Type C 1.6-2.5 

CZC 2.8-4.0 

SBX 7.9-9.0 

10.2 These pH values are preferably measured 
at an oxide concentration in the treating solution of 



15-22 g./l. and at a temperature of 20-30°C. If a 
CCA treating solution has a pH outside the stated 
limits and can be shown that it can be made con- 
forming by the addition of CCA concentrate or 
chromic acid while remaining within the recom- 
mended limits stated in Standard P-5, Sections 4.2, 
5.2 and 6.2, the solution shall be considered con- 
forming to the standard. 



1 1 . STANDARD ADDITIVES. 

The CCA /oil emulsion formulation is recognized 
as a standard additive system for CCA, per the 1991 
Report of Subcommittee P-4.